U.S. patent application number 16/069170 was filed with the patent office on 2019-01-17 for automotive electric fluidic pump.
This patent application is currently assigned to PIERBURG PUMP TECHNOLOGY GMBH. The applicant listed for this patent is PIERBURG PUMP TECHNOLOGY GMBH. Invention is credited to FRANK BUERGER, MICHAEL HAASE, ALESSANDRO MALVASI, VIKTOR SCHROEDER, MARTIN SCHUMACHERS, HARALD SPIERTZ, ANDREAS WULF.
Application Number | 20190020255 16/069170 |
Document ID | / |
Family ID | 55129870 |
Filed Date | 2019-01-17 |
United States Patent
Application |
20190020255 |
Kind Code |
A1 |
BUERGER; FRANK ; et
al. |
January 17, 2019 |
AUTOMOTIVE ELECTRIC FLUIDIC PUMP
Abstract
An automotive electric fluidic pump includes a brushless and
electronically commutated electric drive motor. The electric drive
motor includes a permanent-magnetic motor rotor which rotates
around a rotation axis and includes rotor poles, stator-sided
electro-magnetic coils, a printed circuit board with openings, at
least two stator-sided Hall sensors arranged on a proximal side of
the printed circuit board to face the permanent-magnetic motor
rotor, and a ferromagnetic back iron member arranged at a distal
side of the printed circuit board to provide a direct magnetic
coupling of the Hall sensors with each other. The Hall sensors are
arranged eccentrically to detect axial magnetic fields of the rotor
poles. The ferromagnetic back iron member comprises axial
protrusions. An axial protrusion extends into an opening of the
printed circuit board. Each axial protrusion faces a Hall
sensor.
Inventors: |
BUERGER; FRANK; (LANGERWEHE,
DE) ; SCHUMACHERS; MARTIN; (SCHWALMTAL, DE) ;
HAASE; MICHAEL; (ERBACH, DE) ; SPIERTZ; HARALD;
(ERKELENZ, DE) ; SCHROEDER; VIKTOR; (LIVORNO,
IT) ; MALVASI; ALESSANDRO; (LIVORNO, IT) ;
WULF; ANDREAS; (DUESSELDORF, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PIERBURG PUMP TECHNOLOGY GMBH |
NEUSS |
|
DE |
|
|
Assignee: |
PIERBURG PUMP TECHNOLOGY
GMBH
NEUSS
DE
|
Family ID: |
55129870 |
Appl. No.: |
16/069170 |
Filed: |
January 13, 2016 |
PCT Filed: |
January 13, 2016 |
PCT NO: |
PCT/EP2016/050553 |
371 Date: |
July 11, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02K 29/08 20130101;
H02K 5/04 20130101; B62D 5/064 20130101; H02K 2211/03 20130101 |
International
Class: |
H02K 29/08 20060101
H02K029/08; B62D 5/06 20060101 B62D005/06; H02K 5/04 20060101
H02K005/04 |
Claims
1-11. (canceled)
12. An automotive electric fluidic pump comprising an electric
drive motor which is brushless and electronically commutated, the
electric drive motor comprising: a permanent-magnetic motor rotor
configured to rotate around a rotation axis and comprising a
plurality of rotor poles; a plurality of stator-sided
electro-magnetic coils; a printed circuit board arranged to lie in
a first transversal plane, the printed circuit board comprising
openings arranged therein; at least two stator-sided Hall sensors
arranged on a proximal side of the printed circuit board to face
the permanent-magnetic motor rotor, the at least two stator-sided
Hall sensors being arranged eccentrically to detect axial magnetic
fields of the plurality of rotor poles; and a ferromagnetic back
iron member arranged at a distal side of the printed circuit board
to provide a direct magnetic coupling of the at least two
stator-sided Hall sensors with each other, the ferromagnetic back
iron member comprising axial protrusions, a respective one of the
axial protrusions being arranged to extend into a respective one of
the openings of the printed circuit board, each axial protrusion
being arranged to face a respective one of the at least two
stator-sided Hall sensors.
13. The automotive electric fluidic pump as recited in claim 12,
wherein the ferromagnetic back iron member is fixed to the printed
circuit board via a soldering.
14. The automotive electric fluidic pump as recited in claim 12,
wherein the ferromagnetic back iron member is configured to define
a closed ring lying in a second transversal plane.
15. The automotive electric fluidic pump as recited in claim 12,
wherein the ferromagnetic back iron member is configured to define
a circular ring.
16. The automotive electric fluidic pump as recited in claim 12,
further comprising: field conducting pins which are arranged
substantially axially, a respective one of the field conducing pins
being assigned to a respective one of the at least two stator-sided
Hall sensors in a proximal direction.
17. The automotive electric fluidic pump as recited in claim 12,
wherein the ferromagnetic back iron member is a metal sheet
body.
18. The automotive electric fluidic pump as recited in claim 12,
wherein each of the axial protrusions are made via a deep-drawing
so as to define a proximal nose.
19. The automotive electric fluidic pump as recited in claim 12,
wherein, the printed circuit board further comprises a thickness,
and each of the axial protrusions comprises an axial length which
is more than 80% of the thickness of the printed circuit board.
20. The automotive electric fluidic pump as recited in claim 12,
wherein, each of the openings in the printed circuit board comprise
a diameter, and each of the axial protrusions comprises an outer
diameter which is at least 0.7 mm smaller than the diameter of the
opening in the printed circuit board corresponding thereto.
21. The automotive electric fluidic pump as recited in claim 12,
wherein each of the axial protrusions comprises a conical
shape.
22. The automotive electric fluidic pump as recited in claim 12,
wherein each of the axial protrusions comprises a collar portion at
a distal end.
Description
CROSS REFERENCE TO PRIOR APPLICATIONS
[0001] This application is a U.S. National Phase application under
35 U.S.C. .sctn. 371 of International Application No.
PCT/EP2016/050553, filed on Jan. 13, 2016. The International
Application was published in English on Jul. 20, 2017 as WO
2017/121472 A1 under PCT Article 21(2).
FIELD
[0002] The present invention relates to an automotive electric
fluidic pump with a brushless and electronically commutated
electric drive motor and with a plurality of Hall sensors for the
accurate detection of the rotational rotor position.
BACKGROUND
[0003] The drive motor comprises a permanent-magnetic motor rotor
rotating around a rotation axis and being provided with a plurality
of rotor poles, a plurality of stator-sided electro-magnetic coils,
and a printed circuit board lying in a transversal plane. The drive
motor further comprises at least two stator-sided Hall sensors
arranged on the printed circuit board at a proximal side thereof
and facing the motor rotor, wherein the Hall sensors are arranged
eccentrically so that the Hall sensors detect the axial magnetic
fields of the rotor poles. A ferromagnetic back iron member is also
provided at a distal side of the printed circuit board for a direct
magnetic coupling of the Hall sensors with each other.
[0004] A respective automotive electric fluidic pump having a
brushless and electronically commutated electric drive motor is
described in EP 2 701 291 A1. The position of the motor rotor is
detected by three Hall sensors mounted on a PCB (printed circuit
board) which are connected to three field conducting pins. An
interference ring is mounted on a side of the PCB opposite to a
side where the Hall sensors are provided to the PCB.
[0005] The exact detection of the rotational rotor position of the
motor rotor of an automotive fluidic pump, which is driven by an
electronically commutated drive motor, is important for a safe and
energy-efficient operation. An accurate control of the drive motor
requires an exact detection of the rotational rotor position of the
motor rotor. An accurate motor control avoids undesired operation
states, such as start-up problems, so-called toggling etc. Such
undesired operation states can in particular occur with
displacement fluidic pumps because of a wide range of torques. The
total energy consumption is also minimized by an accurate timing of
the commutation in the stator coils.
[0006] Hall sensors are used for accurate rotor position detection;
the Hall sensors can be arranged axially of the motor rotor. The
Hall sensors thereby detect the passing rotating magnetic fields
generated by the rotor poles. The absolute field strength of the
magnetic field of the rotor poles detected by the Hall sensor and
the strength of interference fields are relevant for the accuracy
of the rotor position detection with Hall sensors.
SUMMARY
[0007] An aspect of the present invention is to provide an
automotive electric fluidic pump having a brushless and
electronically commutated electric drive motor which detects the
rotational rotor position more accurately and which can be
manufactured more economically.
[0008] In an embodiment, the present invention provides an
automotive electric fluidic pump which includes an electric drive
motor which is brushless and electronically commutated. The
electric drive motor includes a permanent-magnetic motor rotor
configured to rotate around a rotation axis and comprising a
plurality of rotor poles, a plurality of stator-sided
electro-magnetic coils, a printed circuit board arranged to lie in
a transversal plane, at least two stator-sided Hall sensors
arranged on a proximal side of the printed circuit board to face
the permanent-magnetic motor rotor, and a ferromagnetic back iron
member arranged at a distal side of the printed circuit board to
provide a direct magnetic coupling of the at least two stator-sided
Hall sensors with each other. The printed circuit board comprises
openings arranged therein. The at least two stator-sided Hall
sensors are arranged eccentrically to detect axial magnetic fields
of the plurality of rotor poles. The ferromagnetic back iron member
comprises axial protrusions. A respective one of the axial
protrusions is arranged to extend into a respective one of the
openings of the printed circuit board. Each axial protrusion is
arranged to face a respective one of the at least two stator-sided
Hall sensors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention is described in greater detail below
on the basis of embodiments and of the drawings in which:
[0010] FIG. 1 shows a schematic presentation of an electrical
automotive fluid pump comprising an electric drive motor and a
pumping unit;
[0011] FIG. 2 shows a longitudinal section of the electric drive
motor of the electrical automotive fluid pump shown in FIG. 1;
and
[0012] FIG. 3 shows a top view of the printed circuit board
comprising the ferromagnetic back iron member.
DETAILED DESCRIPTION
[0013] The automotive electric fluidic pump according to the
present invention provides a ferromagnetic back iron member which
directly magnetically couples the Hall sensors with each other. The
ferromagnetic back iron member comprises axial protrusions which
respectively extend into openings of the printed circuit board.
Each protrusion faces the corresponding Hall sensor. The distance
is thereby minimized between the ferromagnetic sensor circuit
member and the Hall sensors. The magnetic circuit for the magnetic
fields emitted in an axial direction by the rotor poles is
significantly improved, i.e., the magnetic resistance in the Hall
sensor circuit is reduced.
[0014] A magnetic gap is provided between the side of the Hall
sensors and the rotor poles. The quality of the magnetic circuit is
improved by the ferromagnetic back iron member. The signal/noise
ratio is thereby increased significantly at each Hall sensor so
that the rotor position can be determined more accurately.
Undesired operational states of the rotor can be avoided and the
quality of the motor control can be reduced so that the motor
control can be provided simply and inexpensively.
[0015] In an embodiment of the present invention, the ferromagnetic
back iron member can, for example, be fixed to the printed circuit
board by soldering. The sensor circuit member can thereby be
connected easily and quickly to the printed circuit board. The
automotive electric fluidic pump can accordingly be manufactured
more economically.
[0016] In an embodiment of the present invention, the ferromagnetic
back iron member can, for example, define a closed ring lying in a
transversal plane. The magnetic coupling of the Hall sensors and
the ferromagnetic back iron member are improved by a closed ring.
The magnetic resistance in the Hall sensor circle is accordingly
decreased so that the signal quality is improved.
[0017] The ferromagnetic back iron member can, for example, define
a circular ring. A region in the middle of the circular ring is
thereby free so that a rotor shaft can extend through the ring.
[0018] In an embodiment of the present invention, field conducting
pins can, for example, be provided which are arranged substantially
axially and which are assigned to each Hall sensor proximally. The
Hall sensors can therefore be arranged remote with an axial
distance from the motor rotor so that the Hall sensors may be
arranged together with the motor controller on a single printed
circuit board. The proximal end of the field conducting pin is
provided axially as close as possible to the motor rotor. The field
conducting pin bundles and forwards the axial magnetic field of the
rotor poles to the respective Hall sensor with relative low
magnetic loss. The field conducting pin together with the
ferromagnetic back iron member provides a low-loss magnetic circuit
which provides a strong signal for the Hall sensors. The Hall
sensors can accordingly be arranged remote from the stator-coils so
that the magnetic interferences caused by the magnetic coils are
relatively small. The signal is nevertheless so high that the motor
controller can have a relatively simple design, thereby saving
manufacturing costs.
[0019] In an embodiment of the present invention, the ferromagnetic
back iron member can, for example, be a metal sheet body. A
ferromagnetic back iron member made of a metal sheet body is
inexpensive and can be easily processed by stamping and
deep-drawing. The ferromagnetic back iron member can therefore be
manufactured economically.
[0020] In an embodiment of the present invention, the protrusions
can, for example, be made by deep-drawing and define proximal
noses. No further element needs to be provided to the ferromagnetic
back iron member. The ferromagnetic back iron member can
accordingly be made from a single piece. Some manufacturing steps
can thereby be saved. The ferromagnetic back iron member can thus
be manufactured economically.
[0021] In an embodiment of the present invention, each protrusion
can, for example, have an axial length of more than 80% of the
thickness of the printed circuit board. According to the present
invention, the axial length of the protrusions is the length of the
protrusions extending into the openings. The distance between the
protrusion of the ferromagnetic back iron members and the Hall
sensors can thereby be made small, thereby improving signal
quality.
[0022] In an embodiment of the present invention, each protrusion
can, for example, have an outer diameter which is at least 0.7 mm
smaller than the diameter of the corresponding opening in the
printed circuit board. The ferromagnetic back iron member can
thereby also be mounted to the printed circuit board if the
position of the openings does not exactly match the positions of
the protrusion. The manufacturing tolerances can thereby be less
strict, thereby allowing the electric fluidic pump to be
manufactured more economically.
[0023] In an embodiment of the present invention, each protrusion
can, for example, be formed conically. According to the present
invention, the diameter of the conical protrusion decreases with
decreasing distance to the Hall sensors. The protrusions can, for
example, be formed as truncated cones.
[0024] In an embodiment of the present invention, each protrusion
can, for example, be provided with a collar portion at a distal end
thereof. A collar portion according to the present invention is a
ring-shaped portion which surrounds the protrusions in a
transversal plane. The maximal depth of the protrusion protruding
into the opening is thereby limited. The final minimal distance
between the protrusion and the Hall sensor is thereby precisely
adjusted.
[0025] Further advantages will become evident by the following
detailed description of an embodiment of the present invention in
combination with the drawings.
[0026] FIG. 1 shows a schematic view of an electrical automotive
fluid pump 10 comprising two modules, i.e., an electric drive motor
12 and a pumping unit 14. The pumping unit 14 can be a displacement
pump, for example, a vane pump, a rotary vane pump or a piston
pump. The pumping unit 14 also could be a flow pump, for example, a
centrifugal pump or an impeller pump.
[0027] FIG. 2 shows a longitudinal section of the electric drive
motor 12. The electric drive motor 12 is a brushless and
electronically commutated electric drive motor 12. The electric
drive motor 12 comprises a permanent-magnetically excited motor
rotor 30 with four rotor poles 38.sub.1-38.sub.4, in each of which
a permanent magnet 36 is embedded. Six electro-magnetic coils 40
are arranged on a stator side, which electro-magnetic coils 40
generate a rotating rotor magnetic field. The electro-magnetic
coils 40 are arranged in a motor housing 20. The motor housing 20
is defined by a housing cup 22 and a housing cover 24. The motor
rotor 30 comprises a motor shaft 32 which directly drives a pump
shaft of the pumping unit 14.
[0028] A printed circuit board 50 is arranged at an axial end side
of the electric drive motor 12 facing away from the pumping unit 14
and lying in a transversal plane. The printed circuit board 50
comprises a board body 52 having conductor paths 54 at a proximal
side thereof. The proximal side of the board body 52 is the side
axially facing the motor rotor 30. The distal side of the board
body 52 is the side being axially more remote from the motor rotor
30. The control electronics and the power electronics of the motor
control are both arranged on the proximal side of the board body
52. Three Hall sensors 60.sub.k, 60.sub.2, 60.sub.3 are further
arranged on the proximal side of the board body 52. The Hall
sensors 60.sub.1, 60.sub.2, 60.sub.3 are arranged in approximately
the same radius to a motor axis, which is the rotation axis 61, as
the permanent magnets 36 of the motor rotor 30.
[0029] The power electronics of the printed circuit board 50 is
electrically connected to the electro-magnetic coils 40 by the
conductor paths 54 and by axial connecting lines 66. Each Hall
sensor 60.sub.1, 60.sub.2, 60.sub.3 is respectively associated with
a ferromagnetic axial field conducting pin 62.sub.k, 62.sub.2,
62.sub.3 which is placed proximally to the respective Hall sensor
60.sub.k, 60.sub.2, 60.sub.3. The proximal longitudinal ends of the
ferromagnetic axial field conducting pins 62.sub.1, 62.sub.2,
62.sub.3 only have a small distance from the axially opposite end
of the motor rotor 30.
[0030] A ferromagnetic back iron member 70 is arranged as shown in
FIG. 2 on the distal side of the printed circuit board 50. The
ferromagnetic back iron member 70 is made of a one-piece body made
of a ferromagnetic material and is soldered to the printed circuit
board 50. The ferromagnetic back iron member 70 comprises three
axial conically shaped protrusions 71.sub.k, 71.sub.2, 71.sub.3
extending into corresponding openings 72.sub.k, 72.sub.2, 72.sub.3
of the printed circuit board 50 so that each axial protrusion
71.sub.1, 71.sub.2, 71.sub.3 axially faces a Hall sensor 60.sub.1,
60.sub.2, 60.sub.3. A relatively small gap 74 is formed between the
axial protrusion 71.sub.1, 71.sub.2, 71.sub.3 and the respective
Hall sensor 60.sub.1, 60.sub.2, 60.sub.3.
[0031] FIG. 2 further shows that the printed circuit board 50
including the control electronics, the Hall sensors 60.sub.k,
60.sub.2, 60.sub.3, and the axial field conducting pins 62.sub.k,
62.sub.2, 62.sub.3 are cast into a monolithic plastic casting 55.
The conductor paths 54 of the printed circuit board 50 are
connected to a motor plug 68 by connecting lines.
[0032] FIG. 3 shows a top view of the printed circuit board 50
comprising the ferromagnetic back iron member 70. The ferromagnetic
back iron member 70 is formed as a ring-shaped member. Each
protrusion 71.sub.1, 71.sub.2, 71.sub.3 is surrounded by a circular
collar portion 76 lying in a transversal plane, both covering the
opening 72.sub.1, 72.sub.2, 72.sub.3.
[0033] As can be seen in FIG. 2, a magnetic circuit is formed by
the ferromagnetic back iron member 70 on the distal side of the
Hall sensors 60.sub.1-60.sub.3, the axial field conducting pins
62.sub.1, 62.sub.2, 62.sub.3 proximal to the Hall sensors
60.sub.1-60.sub.3, and the ferromagnetic motor rotor 30. The
overall total magnetic resistance is therefore low. The magnetic
field generated by the rotor permanent magnets 36 generates a
relatively high field strength in the region of the Hall sensors
60.sub.1-60.sub.3. A high signal/noise ratio is therefore present
at the Hall sensors 60.sub.1-60.sub.3 which enables a series of
constructive and conceptual simplifications to reduce the electric
power loss and simplify manufacturing.
[0034] The present invention is not limited to embodiments
described herein; reference should be had to the appended
claims.
REFERENCE NUMERALS
[0035] 10 electric automotive fluid pump [0036] 12 electric drive
motor [0037] 14 pumping unit [0038] 20 motor housing [0039] 22
housing cup [0040] 24 housing cover [0041] 30 motor rotor [0042] 32
motor shaft [0043] 36 permanent magnet [0044] 38.sub.1-38.sub.4
rotor poles [0045] 40 electro-magnetic coils [0046] 50 printed
circuit board [0047] 52 board body [0048] 54 conductor path [0049]
55 monolithic plastic casting [0050] 60.sub.1-60.sub.3 Hall sensors
[0051] 61 rotation axis [0052] 62.sub.1-62.sub.3 ferromagnetic
axial field conducting pins [0053] 66 axial connecting line [0054]
68 motor plug [0055] 70 ferromagnetic back iron member [0056]
71.sub.1-71.sub.3 protrusions [0057] 72.sub.1-72.sub.3 openings
[0058] 74 gap [0059] 76 collar portion
* * * * *